Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

356
FXUS63 KLOT 231911
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
211 PM CDT Tue Jun 23 2026

.KEY MESSAGES...

- Chance of thunderstorms returns Wednesday, some possibly
  becoming strong in the afternoon. Periodic, but low, chances
  for storms then continue through the end of the week into the
  weekend.

- Turning hotter and more humid into early next week.

&&

.DISCUSSION...
Issued at 211 PM CDT Tue Jun 23 2026

Main forecast concern is thunderstorm chances Wednesday into
Wednesday night as an upper level trough and associated surface
low moves across the Great Lakes region. Showers and scattered
thunderstorms across MN are expected to continue moving
southeast into south/central WI tonight. There is still quite a
bit of uncertainty regarding how far south this activity may
move, possibly reaching far northern IL in the predawn hours
with a bit better chance for at least showers across northern IL
Wednesday morning. As a cold front moves across the area
Wednesday afternoon into Wednesday evening, scattered
thunderstorms will be possible and while instability may be
limited, the wind field is sufficient for any organized storms
to possibly become strong to severe and trends will need to be
monitored.

Models are slowly trending further south with precip chances for
Thursday and Friday, though still chances across the southern
cwa, especially later Friday into Friday night. There will still
be a chance for showers and thunderstorms over the weekend as
the upper ridge builds across the area. The best timing
continues to fall in the Saturday afternoon to Sunday afternoon
time frame, with perhaps the best chance now looking to be in
the late Saturday night/early Sunday morning time period. Quite
a bit of uncertainty, but it will need to be monitored for
possible strong storms/heavy rain.

The ridge then builds into the region Sunday into Monday with
warmer and more humid air spreading across the region with highs
on Sunday likely in the upper 80s and lower 90s on Monday. While
much of next week currently appears to be very warm/hot and
humid, there are concerns for how close the local area will be
to the edge of the ridge and for how close thunderstorm
activity may evolve, especially by Monday night into Tuesday,
which could have large impacts on temperatures. cms

&&

.AVIATION /18Z TAFS THROUGH 00Z THURSDAY/...
Issued at 1236 PM CDT Tue Jun 23 2026

Primary forecast concern is the chance of thunderstorms on
Wednesday.

Northeast winds for the Chicago terminals this afternoon will
become light southeasterly this evening and then turn southerly
overnight and southwest Wednesday morning. Gusts into the 20kt
range are expected for much of Wednesday. Light and variable
winds are expected across much of northwest and north central IL
into this evening and then winds will turn light southerly
overnight.

Scattered showers and possibly a few thunderstorms may move
across far northern IL Wednesday morning with showers possible
across the terminals late Wednesday morning into Wednesday
afternoon. The best chance of thunderstorms for the terminals
appears to be mid/late Wednesday afternoon and possibly
lingering into Wednesday evening. Confidence for both coverage
and timing is low and for now have included only prob thunder
mention for the new ORD/MDW 30 hour tafs. cms

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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